ECOSTAT WORKSHOP ON ALIEN SPECIES AND THE EC WATER FRAMEWORK DIRECTIVE

17-18 June 2009, Ispra, Italy

FINAL REPORT

Alison Lee, Joint Nature Conservation Committee, UK

Participants:

Phil Boon (PB) (Chairman)Scottish Natural HeritageUnited Kingdom

Kestutis Arbaciauskas (KA)Institute of EcologyLithuania

Enric Ballesteros (EB)Centre for Advanced Studies of BlanesSpain

Vincent Bertrin (VB)CemagrefFrance

Juergen Boehmer (JB)Bioforum GmbHGermany

Ana Cristina Cardoso (AC)EC Joint Research CentreItaly

Piero Genovesi (PG)Chair IUCN Invasive Species Specialist GroupItaly

Francesca Gherardi (FG)University of FirenzeItaly

Melanie Josefsson (MJ)Swedish Environmental Protection AgencySweden

Saa Kabuta (SK)Centre for Water Management, RijkswaterstaatThe Netherlands

Alison Lee (AL)Joint Nature Conservation CommitteeUnited Kingdom

Anna Occhipinti (AO)University of PaviaItaly

Maria Antonietta Pancucci-Papadopoulou (MP)

Hellenic Centre for Marine ResearchGreece

Nicolas Poulet (NP)Onema - French National Water AgencyFrance

Beatriz Rodriguez-Labajos (BR) Catalan Water AgencySpain

Ursula Schmedtje (US)EC DG EnvironmentBelgium

Franz Schöll (FS)Federal Institute of HydrologyGermany

Nomiki Simboura (NS)Hellenic Centre for Marine ResearchGreece

Gert Van Hoey (GV)Institute forAgriculture and FisheryBelgium

Jochen Vandekerkhove (JV)EC Joint Research CentreItaly

1.0Introduction and Aims of Workshop

1.1PB welcomed everyone to the workshop and introductions were made. AC and JV were thanked for arranging and hosting the workshop, and AL was thanked for writing up a report of the workshop.

1.2PBgave an introductory presentation to explain the background to the workshop. Alien species are not specifically mentioned in the Water Framework Directive (WFD) but constitute a pressure and detract from naturalness. Consequently, a workshop was held in Brussels in March 2006 to discuss how alien species might be incorporated within WFD implementation. PB presented the workshop outcomes to a meeting of ECOSTAT in July 2006, after which the European Commission agreed to include alien species as an item in ECOSTAT’s work programme for 2007-2009.

1.3An ECOSTAT steering group was set up, which met in The Netherlands in September 2007 to plan a further workshop in Bordeaux in April 2008. Various issues were discussed includingdefinitions of terms, developing lists of alien species for assessment, ecological status classification, risk assessment and monitoring. The conclusions from Bordeaux were presented to ECOSTAT in October 2008. In February 2009, a questionnaire was sent out to all Member States, asking for detailed opinion or information on topics such asterms and definitions, alien species lists, approaches to monitoring and approaches to classification. Replies were received from 24 out of 27 EU countries, and Norway. Some countries submitted more than one response, so there were 30 replies in total. Results were collated and analysed by JV and AC.

1.4The results from the questionnaire were presented to ECOSTAT in April 2009, after which it was agreed to continue the ongoing informal information exchange on this topic in the ECOSTAT work programme for 2010-2012.

1.5Workshop aims and objectives:

  • To keep a clear focus on ecological status classification for the WFD.
  • To present the questionnaire results and use these to form the basis for discussions.
  • To discuss terms and definitions and the need for standard lists of alien species.
  • To reach consensus on the approach fordealing with alien species issues under the WFD, particularly in classification of ecological status.
  • To consider the use of ‘biopollution indices’.
  • To produce a workshop report and present conclusions to ECOSTAT in October 2009.

2.0Topic A – Defining the Basic Terms

2.1Summary of questionnaire responses (presentation by Jochen Vandekerkhove).

2.1.1Question 1: How are alien species defined? Response: The majority use the definition as given in the Convention on Biological Diversity (CBD), ‘A species, subspecies or lower taxon, introduced outside its natural past or present distribution; includes any part, gametes, seeds, eggs, or propagules of such species that might survive and subsequently reproduce’. Other countries use minor variations of the CBD definition or have no single agreed definition in use.

2.1.2Question 2: Are translocated native species considered as alien species? Response: opinion was split equally, with smallercountries generally responding ‘no’, and larger countries generally responding ‘yes’.

2.1.3Question 3: Are casual alien species considered as alien species? Response: The majority responded ‘yes’, particularly where these have an impact on native species.

2.1.4Question 4:Are species that are present as a result of climate change considered as alien species? Response: This was a complex question with almost half of respondents unsure. Answers highlighted the difficulty in separating climate change from other anthropogenic impacts, and also human mediated introductions from natural expansion in species ranges.

2.1.5Question 5: Are all introduced species considered as alien species, regardless of the date of introduction? Response: Just over half the replies said ‘yes’. Various dates were suggested, which fell into two categories: ecologically relevant or arbitrary (linked to legislation). Dates in the former category included the discovery of America (1492) and the opening of the Suez Canallinking the Mediterranean Sea with the Red Sea (1869).

2.1.6Question 6: Is it useful to apply a historical date as one of the criteria to determine non-nativeness of a species? Response: 19 replied ‘yes’ provided that dates are ecologically relevant. It was suggested that dates should be applied by region, or be specific to WFD biological quality elements. 10 replied ‘no’ for practical reasons (lack of data) or fundamental reasons, i.e. that only human mediation should be considered.

2.2Discussion on definitions

2.2.1A discussion paper by PB and AC was presented to ECOSTAT in October 2008, ‘Using alien species data in assessing ecological status under the WFD: towards a European approach’. Delegates discussed the list of definitions presented in Annex 1 of this paper, as follows: pressure, significant pressure, alien species, invasive alien species, casual alien species, establishment, introduction, intentional introduction and native species. It was agreed that terms given in the CIS guidance documents on WFD implementation and the CBD glossary should be adopted where possible.

2.2.2Some changes were made to the list of definitions during discussion, and PB offered to edit these following further consultation after the workshop. The final agreed list is presented below.

  • Pressure: The direct environmental effect of an anthropogenic activity(driver), for example, a change in flow or a change in the water chemistry of surface and groundwater bodies (CIS guidance document no. 3[1], modified).
  • Significant pressure: In the context of the WFD, a pressure that, on its own, or in combination with other pressures, would be liable to cause a failure to achieve the environmental objectives set out under Article 4 (CIS guidance document no. 3).
  • Alien species[2]:A species, subspecies, or lower taxon introduced outside its natural past or present range; includes any part, gametes, seeds, eggs, or propagules of such species that might survive and subsequently reproduce (CBD).
  • Invasive alien species[3]: An alien species whose introduction and/or spread threaten biological diversity (CBD).
  • Casual alien species:Alien species that may flourish and even reproduce occasionally in an area, but which do not form self-sustaining populations, and which rely on repeated introductions for their persistence (McNeely et al.,2001[4]).
  • Establishment:The process of an alien species in a new habitat successfully producing viable offspring with the likelihood of continued survival (CBD).
  • Introduction:The movement by human agency, indirect or direct, of an alien species outside of its natural range (past or present). This movement can be either within a country or between countries or areas beyond national jurisdiction[5].(CBD)
  • Note:Delegates agreed that it was not necessary to define the terms ‘intentional introduction’ and ‘native species’.

3.0Topic B – Developing Lists of Alien Species

3.1Summary of questionnaire responses (presentation by Jochen Vandekerkhove).

3.1.1Question 7: Are there monitoring programmes specifically designed for the detection of predefined alien species or the expansion of their ranges? Response: Yes (14), No (16). Monitoring tends to be regionally focused, project based or voluntary. Only a few national and long-term monitoring programmes exist. These tend to be driven by the needs of human health, livestock or economics rather than environmental needs.

3.1.2Question 8: Would the routine monitoring programmes detect plants, invertebrates and fish in each of the WFD surface water types? Response: Plants, invertebrates and fish are equally well covered, but rivers and lakes are covered better than coastal and transitional waters. Some countries also monitor reptiles and parasites.

3.1.3Question 9: Are lists of alien species available? Response: The vast majority (27) of respondents indicated that their country had lists in some form though coverage varied between regions, habitat types and organism groups. Lists are maintained by different organisations and managed in different ways, e.g. via the web, or in books, reports or papers. Consequently, there are issues with accessibility and compatibility within and between countries.

3.1.4Responses to question 9 suggested a need for harmonisation and centralisation of lists across Europe. A centralised EU alien species database, network or centre could facilitate information exchange, develop and maintain alien species lists, establish and update networks of alien species experts, establish early warning systems and influence rapid action to control or eradicate new arrivals of alien species. It could also use centralised funding to support meetings of expert groups, awareness raising campaigns, monitoring, and measures for the eradication and control of alien species.

3.1.5JV described each of the following European alien species networks/databases. None of them covers all groups of organisms or the whole of Europe.

  • DAISIE: Delivering Alien Invasive Species Inventories for Europe. (This is a time limited project and is not supported by long-term funding for maintenance.)
  • NOBANIS: North European and Baltic Network on Invasive Alien Species.
  • CIESM: International Commission for Scientific Exploration of the Mediterranean Sea. (This is confined to a limited number of marine species.)
  • EPPO: European and Mediterranean Plant Protection Organisation.
  • ERNAIS: European Research Network on Aquatic Invasive Species. (A network of alien species experts from across Europe.)

3.1.6JV also described three networks/databases with global coverage:

  • NISBASE: International Non-indigenous Species Database Network
  • GISIN: Global Invasive Species Information Network
  • GISD: Global Invasive Species Database

3.2Discussion on alien species lists

3.2.1General lists or WFD-specific lists? Delegates agreed that it is important for countries to create and maintain lists of alien species, building upon current tools and databases where possible (e.g. DAISIE). These lists will normally be used for general purposes, but should be adaptable for specific use in WFD implementation. For example, lists could be organised at different spatial scales such as river basins or water bodies.

3.2.2Which taxonomic groups should be included? Delegates agreed that all taxonomic groups believed to be exerting pressures on water bodies must be included. GV raised bacteria and protozoa as a query. Most countries have not included these for practical reasons, though they can have an impact on ecological processes.

3.2.3Which species should be included? Improvements are needed to ensure that lists cover all alien species relevant to rivers, lakes and transitional and coastal waters. There was general support for including ‘translocated native’ species and ‘casual alien’ species within these lists as they cause as much damage as other alien species in certain areas or circumstances. PB mentioned that the UKhas included three riparian species that are known to have impacts on aquatic ecosystems within the WFD alien species list: Japanese knotweed(Fallopia japponica), giant hogweed(Heracleum mantegazzianum) and Himalayan balsam(Impatiens glandulifera). US suggested that riparian species should only be considered where they are observed to have a direct effect on the biological elements.

3.2.4Should alien species lists include ‘impact’ categories? All delegates agreed that lists should include impact categories such as ‘high’, ‘low’ or ‘unknown’ impact, to indicate the level of risk associated with each alien species. The allocation to a category may change over time as research improves our understanding. PG mentioned that DAISIE provides information on the types and level of impact associated with each species.

3.2.5Should dates of introduction determine which species are considered aliens? The questionnaire indicated that a wide range of dates has been adopted by those countries that use dates in determining if species should be considered alien. Delegates’ opinions were similarly varied. DAISIE uses 1500, representing the discovery of the Americas. However, many delegates supported use of a later date such as 1700 (as reference data are more widely available) or even 1900 (due to increasing ecological connections and the subsequent increase in spread of alien species). US supported the use of regionally relevant dates, linked for example to the opening of new pathways such as canals. AC was concerned that such regional variations would cause difficulties in working across Europe in a harmonised approach. SKstated that dates are not relevant, as the most important consideration is the level of damage caused by each species. A number of delegates also agreed with this viewpoint. No consensus was reached on this question.

3.2.6How should lists and aliens species data be harmonised and maintained across Europe? All agreed that this question was beyond the scope of the workshop, although everyone supported the development of a more harmonised approach. This should build upon tools and databases already in use (e.g. DAISIE, CIESM and NOBANIS). PG stressed the importance of tracking the spread of alien species to new areas and developing a pan-European ‘early warning’ system to encourage preventative measures.

4.0Topic C – Options for Ecological Status Classification

4.1Introduction to different options (presentation by Phil Boon).

4.1.1PB described four options for dealing with alien species in ecological status classification, and listed possible advantages and disadvantages associated with each. These options came from the Bordeaux workshop, and were presented to the ECOSTAT meeting in October 2008.

  • Option 1: A water body is classified using pressure-based classification tools, and then the classification is modified in an additional step based on alien species, with the final result being either high, good, or less than good status.
  • Option 2: This option is similar in principle to option 1, but it is based upon quantitative assessments linking the abundance or percentage cover of alien species to the five WFD quality classes.
  • Option 3: The classification process for each biological quality element is undertaken as normal without any additional assessment made of alien species, on the assumption that the classification tools can adequately detect any impacts caused by alien species.
  • Option 4: Water bodies are classified without explicitly taking account of alien species. A separate ‘risk assessment’ for alien species is undertaken, by including various ‘biopollution’ indices for the risk and impact of alien species. This risk assessment is then published alongside the water body classification and used to influence the programmes of measures.

4.2Summary of questionnaire responses (presentation by Jochen Vandekerkhove).

4.2.1Question 10: Are alien species explicitly taken into account in ecological status assessment and classification under the WFD? Responses varied slightly between habitats, but the majority responded ‘no’ or ‘not applicable’, citing practical reasons (lack of alien species lists or data on impacts) or conceptual reasons (alien species are already accounted for by classification tools).

4.2.2Question 11: In which water bodies are alien species absent when applying the protocol for ecological status? This question was irrelevant to most countries.

4.2.3Question 12: Under which option does the current WFD ecological status assessment fall? The majority use option 3, for rivers (18), lakes (18) and transitional and coastal waters (14).

4.2.4Question 13: Which option would be the most appropriate considering both feasibility and usefulness in ecological status assessment and classification under the WFD? The vast majority (26) supported options 3 or 4 as the most appropriate option and only a few (4)supported options 1 or 2.

4.3OPTION 1: Introduction and case study (presentation by Phil Boon).

4.3.1In the UK, alien species are used in ecological status classification both for high and good ecological status. After classification (using biological tools), water bodies are then downgraded from high status if a ‘high impact’ alien species is established. If a ‘high impact’ species is established and demonstratesmore than a slight adverse impact, then water bodies are downgraded to less than good status.

4.3.2PB presented examples of the Tiel Burn and River Earn in central Scotland. Both rivers were classified at good or high status using biological classification tools, but subsequently downgraded to moderate status owing to the establishment of North American signal crayfish (Pacifastacus leniusculus) and its known impact on freshwater ecosystems.

4.4Discussion on option 1

4.4.1NP was concerned that a large number of water bodies would be downgraded from high status under option 1, simply due to the presence of alien species (as demonstrated impact is not necessary for downgrading from high status). These water bodies may remain at lower status classes for a long time, as control mechanisms are currently insufficient to deal with alien species problems. PB stressed that alien species should not be ignored in WFD classification simply because they are difficult to deal with. In addition, downgrading sites highlights an important educational message, helping to reduce the danger of spread to other water bodies.

4.4.2FS suggested that the UK’s biological classification tools may not be adequate if impacts from alien species are not detected within the main classification. PB countered this viewpoint using the example of zebra mussel(Dreissena polymorpha) in Ireland where a number of lakes have become infested with this species. Using the phytoplankton assessment tool would indicate excellent water quality, but simply as a consequence of excessive filter feeding by the zebra mussel population. Consequently, the approach of downgrading status classesis justified using option 1.

4.4.3PG supported option 1 as a clear, easily applicable approach, but suggested that it could be more focused on trends in range and prevention of new introductions, otherwise more and more water bodies will be downgraded with few opportunities for improvement. Alien species indicators focus more on these elements. PB agreed, and suggested that biopollution indices used in combination with option 1 might be able to cover these additional elements of risk assessment.